New Holland DCU 19055 – DCU (Dosing Control Unit): UREA Temperature sensor in box (electrical) _high signal _P2045 Reagent -temperature sensor of pump module -short circuit high

The engine management system detects that the voltage signal from the Diesel Exhaust Fluid (DEF / Urea / Reagent) temperature sensor is exceeding the normal operating threshold. A "short circuit high" or "high signal" typically indicates an open circuit (a broken wire or disconnected plug) or a short to a high-voltage power source (such as battery voltage) within the sensor or its wiring harness.

• T6 series (T6.120 to T6.175)
• T7 series (T7.165 to T7.270)
• T8 series
• T9 series
• TS6 series
• CR series (CR6090, CR7090, CR8090, CR9090, CR8.90, CR9.90)
• CX series (CX8070, CX8090)
• WD1504
• WD2505
• Speedrower 160
• Speedrower 220
• Speedrower 260
• LM series (LM6.32, LM7.42)
• TH series (TH7.42)

1. 1

   Inspect the wiring harness between the DCU and the DEF supply module for chafing, melting, or physical damage.

2. 2

   Disconnect the DEF pump module and check the pins for corrosion, moisture, or bent terminals.

3. 3

   Test the ground circuit between the DCU and the DEF fluid supply module for an open circuit.

4. 4

   Test the sensor signal wire for a short to battery voltage.

5. 5

   If the external wiring harness and connectors test perfectly, the fault is isolated to a defective internal temperature sensor inside the DEF supply module.

1. 1

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the DEF supply module (Denoxtronic pump), which is typically mounted near the DEF tank.

3. 3

   Clean the area around the pump to prevent dirt from entering the DEF system.

4. 4

   Disconnect the electrical harness connector from the pump module.

5. 5

   Carefully disconnect the DEF fluid lines (suction, backflow, and pressure lines).

   Note: DEF fluid can be corrosive; clean up any spills with warm water.

6. 6

   Unbolt the mounting hardware and remove the faulty DEF pump module.

7. 7

   Install the new DEF pump module and torque the mounting bolts to factory specifications.

8. 8

   Reconnect the DEF fluid lines and the electrical harness.

9. 9

   Software Programming (Crucial): A new DEF Dosing Control Unit / Pump Module requires software installation and calibration to pair it with the tractor's main ECU.

   This requires the CNH Electronic Service Tool (EST) and dealer passwords.

10. 10

    Clear the fault codes and run a stationary SCR system test/regeneration to verify the repair.